The mother of a 5-day-old boy left in the Sutphin Avenue F train station was arrested yesterday and charged with felony abandonment of a child. Antonia Lopez left her son swaddled in a blanket next to a MetroCard machine at about 8 p.m. on Friday night. He was found and taken to Jamaica Hospital, where he remains healthy. According to Safe Haven laws, Lopez could have dropped the baby off at FDNY or NYPD stations without risk of prosecution.